In the financial industry, checks are commonly printed with MICR characters to facilitate automated processing of those checks. MICR characters are printed using magnetic ink or toner, that is, ink or toner that contains magnetic particles dispersed throughout, so that the characters can be read automatically by a data processing system that includes a suitable electromagnetic read head. One widely used standard for such characters is the E13B standard, which defines with specificity the patterns and relative dimensions of the numerical characters 1, 2, 3, 4, 5, 6, 7, 8, 9 and 0, as well as a number of special characters. The E13B patterns for the numerical characters 1, 2, 3, 4, 5, 6, 7, 8, 9 and 0 are shown in FIG. 1. The ANSI (American National Standards Institute) standard for the E13B character set is ANS X9.100.20.2006 (American National Standard for Financial Services) published by the Accredited Standards Committee X9, Incorporated. This standard is also replicated in other national standards in other countries that use the E13B font, such as the Canadian Payments Association Standard 006 entitled “Standards and Specifications for MICR Encoded Documents”. ANS X9.100.20.2006 is hereby incorporated by reference in its entirety.
With the E13B standard, the characters are automatically read by sensing the vertical shape transitions or “edges” (“vertical” in the sense of being perpendicular to the read direction) of the specially designed standard characters as the characters pass over an electromagnetic read head (or as the read head is passed over the characters). It is the nature of the electromagnetic sensing that it requires high precision in the shape and dimensions of the characters. As the read head passes over the characters (or vice versa), it produces a waveform which has peaks that correspond to the vertical edges of the characters, and the pattern of the peaks enables the character to be recognized. Such vertical edges are referred to herein as “detection edges”, since these edges produce the peaks in the waveform used to indentify the characters.
One of the parameters that determines the amplitude of a peak is the magnetic acuity of a detection edge. The magnetic acuity of a vertical edge is affected by the roughness of the detection edge. A rough detection edge reduces the acuity and therefore reduces the amplitude of the peak, which can make the character unrecognizable to the automated detection system. Limits on the roughness of a detection edge are prescribed in ANS X9.100.20.2006. The distance of the ink from the read head also affects the magnetic acuity; if the magnetic ink is further from the electromagnetic read head, the amplitude of the peak is reduced by the increased distance (which reduces the strength of the magnetic signal).
For E13B MICR characters printed using offset printing, impact printing or electrostatographic printing, the magnetic acuity of the detection edges is relatively independent of the absorbency of the paper that the character is printed on, since the magnetic ink is on or close to the surface of the paper. Moreover, with these printing methods, the roughness of the detection edges is not greatly affected by inward transportation of the magnetic ink due to the absorption of the ink or toner by the paper. Printing of checks is typically done using offset printing, impact printing or electrostatographic printing.
It is also desirable to be able to print checks using inkjet printing. In inkjet printing, tiny droplets of liquid ink are expelled from a print head having a large number of individual nozzles to create a desired pattern on the substrate. One type of liquid ink used in inkjet printing is curable ink, which, following deposition on the substrate, hardens into a solid in response to an environmental factor, such as ultraviolet radiation. Another type of liquid ink used in inkjet printing is aqueous ink, which, after deposition on the substrate, becomes solid as a result of evaporation of the aqueous carrier and absorption of the aqueous carrier into the substrate. Since inkjet printers are commonly used in private homes as part of a home computer system, inkjet printing of checks enables individuals to print their own custom checks at home, providing potential cost savings. For example, G7 Productivity Systems, having an address at P.O. Box 270459, San Diego, Calif. 92198 (www:g7ps.com), has offered a cheque printing kit under the brand VersaCheck®, which includes a Versajette M300 printer (a re-badged Lexmark Z1300 printer), cheque paper, software and a cartridge containing Versaink nano™ aqueous MICR ink. In order to be processed automatically by a financial institution using the E13B standard, such checks would need to include readable E13B MICR characters.
However, for E13B MICR characters printed using inkjet printing, the magnetic acuity of the detection edges can be affected by the absorbency of the paper that the character is printed on. Because of the requirements of the inkjet process, such as avoidance of clogging of the very small passageways often used in inkjet printing, the viscosity of the liquid ink is relatively low and the magnetic material is composed of very small particles. As a result, depending on the type of paper used, the ink may be readily absorbed and the magnetic ink transported from the surface of the paper and into the body of the paper. This increases the roughness (i.e. reduces the sharpness) of the detection edges, as well as increasing the distance between the magnetic ink and the read head.
The above-noted problems with inkjet printing of E13B MICR characters can reduce the amplitude of the peak associated with a detection edge, which can thereby make it more difficult to recognize E13B MICR characters printed using an inkjet process. Where the automated character recognition systems cannot identify a character, then the document must be redirected for costly manual processing.
One technique that has been used in an effort to obviate these difficulties is to print on special papers which contain materials on the surface of the paper or in the body of the paper designed to control the absorbency of the paper and/or the transportation of the ink along the surface of the paper. However, such special types of papers are usually more expensive, and may have a different “look and feel”, than the papers on which E13B MICR characters are normally or preferably printed. Moreover, such special papers may be unsuitable for automatic processing. Thus, in many cases the use of a specialized paper to enable inkjet printing of readable E13B MICR characters may be expensive, infeasible and/or undesirable.